question

To many variables to answer this with the info provided.

the fronius is a ac connect system - the unit does not charge the battery directly its converts the dc solar direct to 110/240 volts. then there is a inverter charger that charges the batteries

the mppt is a dc connect system and charges the battery directly.

so the bluesolar is dependent on the battery being full or not and this will affect its output. ie full and the bluesolar output is reduced.

so a lot more info is nneded toi answer your question.

ie battery voltages over the period

what are the smartsolar settings

ect ect

hi, thanks for the response.
I understand. AC vs DC coupling, overvoltage grid feed....
I have a total of 100 installations on the VRM portal and it's similar everywhere.
including RS450 on canbus.
MPPTs are always controlled by BMS.

I'm trying to find a reason. It does this when the battery is full.
On my installation, I have an external functionality that sets the gridsetpoint to feed into the grid according to the current solar power, consumption and market price. Charging the battery is in the second priority as soon as the market price drops.
As long as this function is active, the MPPTs performance is stable.

So far I see the problem in multis. i have 3ph 48/3000. in DC coupling I have 7.2kwp 150/60 150/45 150/35 and on AC out 4.5kw symo on AC in 6kw symo.

it seems to me that multis cannot stably feed to grid. permanently without a drop in power. they interfere with something in the grid - even though I set the feed to grid only from the battery to limit the possibility of the mppts doing it.
From this I conclude that the problem is in the multis. It cannot work correctly with the grid. Quite a long term problem.
For example, the student does not do this. So it is also possible with a transformer converter. Again it will be a SW problem.
Oh victron developers get it right for once.

But symo doesn't do that - it delivers steadily. this means that the grid parameters are fine.

I will try one test. I will program a function that will charge my battery to a maximum of 80-90% and I will see how the behavior changes when the BMS of the battery still indicates a higher maximum charging current.

Pavel

Hello,

so I watched the change today when the feed to grid was running with the battery at 90% and the BMS allowing more charging current.
Performance stability was significantly better.

Multis deliver power to the grid .... and suddenly drop out. The MPPTs will then start supplying power to the battery before the Multis start supplying power to the grid again.

Symo does not react in any way at that exact moment and delivers steadily. From this I conclude that the network parameters are fine. Voltage approx. 240V, frequency 50.0Hz.

Ve.bus state goes to passthrou many times a day for absolutely no reason.

Multis FW I have 492. Should I upgrade? Does this happen to anyone?